A study employing CRISPR/Cas9 to explore the evolutionary beginnings of some giant viruses finds evidence their large genomes arose from gene duplications.
A genomic analysis of “Klosneuviruses” suggests that they evolved from small viruses that accumulated genetic material over time, but not all virologists are convinced.
Rather than introducing small chunks of DNA as other viruses do, some giant viruses can contribute more than 1 million base pairs to a host’s genome, broadening the ways in which viruses may shape eukaryote evolution.